Leadframe-based module DC bus design to reduce module inductance

ABSTRACT

A DC bus for use in a power module has a positive DC conductor bus plate parallel with a negative DC conductor bus plate. One or more positive leads are connected to the positive bus and are connectable to a positive terminal of a power source. One or more negative leads are connected to the negative bus and are connectable to a negative terminal of a power source. The DC bus has one or more positive connections fastenable from the positive bus to the high side of a power module. The DC bus also has one or more negative connections fastenable from the negative bus to the low side of the power module. The positive bus and negative bus permit counter-flow of currents, thereby canceling magnetic fields and their associated inductances, and the positive and negative bus are connectable to the center portion of a power module.

CROSS REFERENCE TO RELATED APPLICATIONS

[0001] This patent application incorporates by reference in itsentirety, and is a continuation-in-part of, the currently co-pendingU.S. patent application Ser. No. 09/882,708, having a filing date of 15Jun. 2001, naming Scott Parkhill, Sayeed Ahmed, and Fred Flett asinventors, and claims priority from the foregoing application, and anyparents of the foregoing application, under the auspices of 35 U.S.C.§120.

[0002] This patent application incorporates by reference in itsentirety, and is a continuation-in-part of, the currently co-pendingInternational Patent Application No. PCT/US01/29504, having anInternational Filing date of 20 Sep. 2001 and a claimed priority date of20 Sep. 2000, naming Scott Parkhill, Sayeed Ahmed, and Fred Flett asinventors, and claims priority from the foregoing application, and anyparents of the foregoing application, under the auspices of 35 U.S.C.§120 and 35 U.S.C. §363.

[0003] This patent application also incorporates by reference in itsentirety any subject matter previously incorporated by reference intothe foregoing-referenced currently co-pending U.S. and InternationalPatent Applications. In particular, this patent application incorporatesby reference in their entireties the subject matter of U.S. ProvisionalApplication No. 60/233,995, filed Sep. 20, 2000, and entitled,“Leadframe-Based Module DC Bus Design to Reduce Module Inductance,” U.S.Provisional Application No. 60/233,996, filed Sep. 20, 2000, andentitled, “Substrate-Level DC Bus Design to Reduce Module Inductance,”U.S. Provisional Application No. 60/233,993, filed Sep. 20, 2000, andentitled, “EMI Reduction in Power Modules Through the Use of IntegratedCapacitors on the Substrate Level,” U.S. Provisional Application No.60/233,992, filed Sep. 20, 2000, and entitled, “Press (Non-Soldered)Contacts for High Electrical Connect Ions in Power Modules,” and U.S.Provisional Application No. 60/233,994, filed Sep. 20, 2000, andentitled, “Both-Side Solderable Power Devices to Reduce ElectricalInterconnects,” such subject matter being previously incorporated byreference into the currently co-pending U.S. and International PatentApplications.

[0004] Each of the foregoing-referenced applications is herebyincorporated by reference herein in its entirety.

BACKGROUND OF THE INVENTION

[0005] 1. Field of the Invention

[0006] The invention relates to the field of electronics. Morespecifically, the invention relates to direct current buses (“DC buses”)used in power modules.

[0007] 2. Description of the Related Art

[0008] An inverter power module is commonly used to convert directcurrent (“DC”) to alternating current (“AC”) to power a three-phasemotor. The power module typically has three pairs of switches on asubstrate that is secured to the module baseplate. Each switching pairhas a positive or “high” side switch and a negative or “low” side switchfor controlling the flow of electric current. Each switching pair isreferred to herein as a “bridge,” and each half of the switching pair isreferred to as a “half-bridge.” The “high side” of the bridge containsthe positive switches, and the “low side” contains the negativeswitches. By the term “switch” is meant a switching device such as aninsulated gate bipolar transistor (“IGBT”) or Metal Oxide Semiconductor(“MOS”) or Metal Oxide Semiconductor Field Effect Transistor (“MOSFET”).

[0009] Elements may be described herein as “positive” or “negative.” Anelement described as “positive” is shaped and positioned to be at ahigher relative voltage than elements described as “negative” when thepower module is connected to a power source. “Positive” elements arepositioned to have an electrical connection that is connectable to thepositive terminal of a power source, while “negative” elements arepositioned to have an electrical connection that is connectable to anegative terminal, or ground, of the power source. Generally, “positive”elements are located or connected to the high side of the power moduleand “negative” elements are located or connected to the low side of thepower module.

[0010] In a typical power module configuration, the high side switchesare on one side of the module opposite the corresponding low sideswitches. A positive DC lead from a power source such as a battery isconnected to a conducting layer in the high side of the substrate.Likewise, a negative DC lead from the power source is connected to aconducting layer in the low side of the substrate. The switches controlthe flow of current from the conducting layers of each half bridgesubstrate to output leads. Output leads, called “phase terminals”transfer alternating current from the three pairs of switches to themotor.

[0011] Power modules typically have three bridges combined into a singlethree-phase switching module, or single half-bridge modules that may belinked together to form a three-phase switch. As would be understood byone of ordinary skill in the art, the same DC to AC conversion may beaccomplished using any number of switching pairs, and each switchingpair may contain any number of switches. For simplicity and clarity, allexamples herein use a common three phase/three switching pairconfiguration. However, the invention disclosed herein may be applied toa power module having any number of switches.

[0012] Current flows from the positive DC lead to the conducting layeron the high side substrate. Current is then permitted to flow throughthe switching device on the high side to the conducting layer on the lowside. A phase terminal lead allows current to flow from the conductinglayer on the low side to the motor. The current then flows from themotor to the conducting layer on the low side of a second switching pairto the negative DC lead to the power source.

[0013] Current flowing through various paths within the module createsinductances, which in turn results in inductive power losses, reducedefficiency, and the excess generation of heat. When the flow of currentchanges, as in such a high frequency switching environment, largevoltage overshoots often result, further decreasing switchingefficiency. In addition, the DC terminals are commonly attached to oneend of the power module, which forces current to travel further to someswitches, and thus, for some switching configurations, than for others,resulting in non-uniform current loops. Current loops that are notuniform result in uneven or inefficient motor performance.

[0014] These and other problems are avoided and numerous advantages areprovided by the device described herein.

BRIEF SUMMARY OF THE INVENTION

[0015] The present invention provides a DC bus for use in a power modulethat is shaped and positioned to minimize the current loops, thusreducing inductive poser losses. The DC bus is also shaped to permitcounter-flow of electric currents, thereby canceling magnetic fields andtheir associated inductances. The DC bus also allows DC current to flowsymmetrically and directly to the switches of the module. Symmetriccurrent loops in the module result in more even and efficient motorperformance.

[0016] Elements may be described herein as “adjacent” another element.By the term “adjacent” is meant that in a relationship so characterized,the components are located proximate to one another, but not necessarilyin contact with each other. Normally there will be an absence of othercomponents positioned in between adjacent components, but this is not arequirement. By the term “substantially” is meant that the orientationis as described, with allowances for variations that do not effect thecooperation and relationship of the so described component orcomponents.

[0017] In accordance with the present invention, the DC bus for use in apower module has a positive DC conductor bus plate and a negative DCconductor bus plate placed parallel to the positive bus. The positivebus is connected to one or more positive leads, which are connectable toa positive terminal of a power source. The negative bus is connected toone or more negative leads, which are connectable to a negative terminalof a power source. One or more positive connections on the bus arefastenable from the positive bus to the high side of the power modules,and one or more negative connections are fastenable from the negativebus to the low side of the module. The positive bus and the negative buspermit the counter-flow of currents, thereby canceling magnetic fieldsand their associated inductances, and the positive and negative bus areconnectable the power module between the high and low side of themodule. Preferably, the DC bus has separate negative leads and separatepositive leads for each half-bridge on the module. The DC bus may alsoinclude an insulating layer between the positive and negative bus.Preferably, each positive lead is substantially adjacent to a negativelead. The bus may be connected either substantially perpendicular to orsubstantially parallel to the substrate of the power module.

[0018] In another aspect of the invention, a power module for reducinginductance is disclosed. The module has a lead frame for supporting themodule and for providing interconnections to the motor and the powersource. A substrate is connected to the lead frame. There are one ormore pairs of high and low switches at the substrate level of themodule. The DC bus described above is placed in the center portion ofthe power module.

[0019] In yet another aspect, the invention is directed to a method ofreducing inductance in a power module. The method involves allowing DCcurrent to flow symmetrically and directly to the switches of the moduleand permitting counter-flow of electric currents, thereby cancelingmagnetic fields and their associated inductances. The positive andnegative leads are positioned in close proximity to one another therebycanceling the magnetic fields and associated inductances.

[0020] The DC bus and power module disclosed herein provide improvedefficiency and more even motor performance through the cancellation ofmagnetic fields and minimization of current loops. A parallel negativeand positive DC bus provides the added benefit of creating capacitancebetween the plates, which further minimize voltage overshoots producedby the switching process. These and other advantages will becomeapparent to those of ordinary skill in the art with reference to thedetailed description and drawings.

[0021] The foregoing is a summary and thus contains, by necessity,simplifications, generalizations and omissions of detail; consequently,those skilled in the art will appreciate that the summary isillustrative only and is NOT intended to be in any way limiting. Otheraspects, inventive features, and advantages of the devices and/orprocesses described herein, as defined solely by the claims, will becomeapparent in the non-limiting detailed description set forth herein

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S)

[0022]FIG. 1 is an overhead view of the top of the power module.

[0023]FIG. 2 is a perspective view of the power module.

[0024]FIG. 3 is a perspective view of the power module without its topportion and with the substrate exposed.

[0025]FIG. 4 is the side view of the power module.

[0026]FIG. 5 is a cross-sectional front view of the power module withcooling intake and outlet.

[0027]FIG. 6 is a cross-sectional front view of the power module withoutcooling intake and out take.

[0028]FIG. 7 is a cross-sectional side view of the power module with DCbusleads.

[0029]FIG. 8 is a cross-sectional side view of the power module with DCbus leads and phase terminals.

[0030]FIG. 9 is a top overhead view of the devices on the substrate inthe module.

[0031]FIG. 10 is a top overhead view of the printed circuit board in themodule.

[0032]FIG. 11 is a perspective view of the power module and DC bus withthe printed circuit board removed.

[0033]FIG. 12 is a perspective view of the DC bus.

[0034]FIG. 13 is a cross-sectional view of the DC bus.

DETAILED DESCRIPTION OF THE INVENTION

[0035] In accordance with the invention, a DC bus is used in a powermodule, and the DC bus is shaped and positioned to minimize currentloops, voltage overshoots and their associated inductance losses, toprovide for symmetric current flow. Reference is made herein to a powermodule with three phase terminals for use with a three-phase motor andhaving three bridges, each with two switching pairs. As will beappreciated by one of ordinary skill in the art, the disclosed powermodule, DC bus, and method for reducing inductance in a power modulecould be used on a power module with any number of phase terminals andbridges, and having any number of switching pairs. Nonetheless, for easeof description, reference is made to a three-phase power module.

[0036] Referring to FIG. 1, an overhead view of the top of the powermodule is shown. The module has three positive leads 21 that areconnectable to a power source, such as a battery, and three negativeleads 23 that are likewise connectable to the negative terminal of apower source such as a battery, or ground. The module has three sets ofphase terminals 15, 17, and 19.

[0037] The top of the power module is held in place by fasteners (notshown) through bushings 13. The fasteners are bolts, but other types offasteners can be substituted therefore, as will be readily apparent tothose of ordinary skill in the art. A non-conducting strip 25 holdsleads 21 and 23 in place by providing a raised portion into which theleads 21 and 23 may be bolted.

[0038] As will be understood by one of ordinary skill in the art, thepositive leads 21 and negative leads 23 carry direct current from abattery source to the module. As will be better understood by thefollowing discussion, the power module converts the direct current toalternating current. In a three-phase module such as that shown in FIG.1, there are at lease three phase terminals 15, 17 and 19 through whichthe resulting alternating current flows. In the preferred embodiment,there are three sets of two phase terminals 15, 17, and 19.

[0039]FIG. 2 is a perspective view of the power module 29. The modulehas a module frame 11 and top cover 10, which are preferably composed ofplastic. The bottom portion is the cooling header 27 of the module, intowhich a cooling liquid enters, circulates through, and exits, forcooling the module. Sandwiched between the module frame 11 and thecooling header 27 middle portion is the base plate, which contains theprinted circuit board, substrate, and switching devices, and is notshown in this view. FIG. 2 shows the positive leads 21 and negativeleads 23, and phase terminals 15, 17, and 19. The module frame 11 isbolted to the cooling header 27 with bushings 13.

[0040]FIG. 3 is a perspective view of the power module, shown withoutits top cover portion 10 and with the substrate 107 removed. The DC bus31 has a separate positive bus plate and a negative bus plate, as isbetter illustrated in FIGS. 5-6, and 9-13. The DC bus 31 is arrangedperpendicular to the substrate 107. As would be understood by one ofordinary skill in the art, the substrate has conducting layers separatedby an insulating layer for carrying and controlling a current flow. Thesubstrate 107 has a high side 101 and a low side 103. The substrate 107includes switches 33, which can be IGBTs, MOS, or MOSFETs, and diodes 35for controlling current flow. The switches 33 are preferably IGBTs. Theswitches 33 and diodes 35 are electrically connected, preferably by wirebonding.

[0041] As will be understood by one of ordinary skill in the art, directcurrent flows from a power source such as a battery to the positive DCleads 21 and to the DC conductor bus plates 31. Current flows to aconducting layer in the high side 101 of the power module. The currentflows through the switches 33 and diodes 35 on the high side 101 througha conducting plate 37. The conducting plate 37 is connected to aconducting layer in the low side 103 of the power module by a connectionlocated through a cut-out passage 39 underneath the bus bar. Currentthen flows from the conducting layer on the low side 103 through one ofthe sets of phase terminals 15, 17, or 19 to a three-phase motor (notshown). Current from the motor flows back to another set of phaseterminals 15, 17, or 19, where it flows from the conducting layer on thelow side 103 to the negative lead 23 of the bus bar 31 and back to thepower source.

[0042]FIG. 3 also shows pairs of phase terminals 15, 17, and 19. Threesingle phase terminals may be substituted for phase terminal pairs 15,17, and 19. Alternatively, each phase terminal grouping, shown as pairs15, 17, and 19, may include more than two phase terminals. Pairs ofphase terminals 15, 17, and 19 are used for ease of connecting toswitches 33 on the high side 103 of the power module.

[0043] Three positive DC leads 21 and three negative DC leads 23 arealso shown. Each lead 21 and 23 is placed central to a switching pairhalf-bridge corresponding to each of the phase terminals 15, 17, or 19.Although other lead configurations are possible, this placement of DCleads 21 and 23 provides for more uniform current flow as opposed toprevious modules having only a single DC lead.

[0044]FIG. 4 is a side view of the power module, with DC leads 21 and23, phase terminal 15, and module frame 11. The bottom cooling header 27includes an intake for coolant 91 and an outlet for coolant 93.

[0045] Referring now to FIG. 5, a cross-sectional front view of thepower module with cooling intake 91 and outlet 93 is shown. The coolingheader 27 includes a cavity 95 through which a coolant, such as water,may flow. The cavity 95 includes thermal conducting projections 111. Thecooling header 27 is fastened to the base plate 61, which supports thehigh side switching assembly 55 and low side switching assembly 53. Thephase terminal 15 is also shown. FIG. 5 illustrates the cross section ofthe DC bus at the point having DC leads 21 and 23. The DC bus has apositive conductor plate 59 arranged parallel to a negative conductorplate 57. An electrically insulating layer 51, preferably made fromplastic or tape, is placed between the positive bus plate 59 and thenegative bus plate 57. Alternatively, enough space may be left betweenthe plates 57 and 59 to provide an insulating layer of air or siliconegel. The electrically insulating layer 51 permits more uniform spacingand closer spacing between the positive and negative buses 57 and 59.

[0046] Thus, counter flow of current is permitted, thereby canceling themagnetic fields and their associated inductances. In addition, theparallel bus plates 57 and 59 create capacitance. As will be understoodby one of ordinary skill in the art, a capacitor dampens voltageovershoots that are caused by the switching process. Thus, the DC busplates 57 and 59 create a field cancellation as a result of the counterflow of current, and capacitance damping as a result of alsoestablishing a functional capacitance between them. FIG. 5 shows the DCbus plates 57 and 59 placed perpendicular to the high and low sidesubstrates 53 and 55, however, the DC bus plates 57 and 59 may also beplaced parallel to the substrates 53 and 55 and still achieve counterflow of current and reduced inductances.

[0047] In various embodiments at least a portion of the materials,referred to herein, which have not been herein identified, described,and/or understood by one having ordinary skill in the art as conductiveor semi-conductive (e.g., the materials used in module frame 11, topcover 10, the electrically insulating layer 51, etc.), can provideelectrical isolation properties (e.g., dielectric properties such asthose possessed by some plastics and glass). In one implementation, suchdielectric properties include a dielectric strength of approximately 20kV/mm or greater. In another implementation, such dielectric propertiesinclude a dielectric strength of 26 kV/mm. In another implementation,such dielectric properties include an ability to provide dielectricisolation from at or around 2 kV to at or around 5 kV. In anotherimplementation, at least a portion of the materials, referred to herein,which have not been herein identified, described, and/or understood byone having ordinary skill in the art as conductive or semi-conductive,retain their dielectric properties (such as the foregoing-describeddielectric properties) subsequent to undergoing an injection moldingprocess; for example, undergoing injection molding at or around atemperature of 330 degrees centigrade and at or around a pressure of 50mega-Pascals.

[0048] In various embodiments at least a portion of the materials,referred to herein, which have not been herein identified, described,and/or understood by one having ordinary skill in the art as conductiveor semi-conductive (e.g., the materials used in various implementationsof the electrically insulating layer 51, etc.), have varyingthicknesses. In one implementation, where the materials are to provideelectrical isolation between conducting materials (e.g., theelectrically insulating layer 51 between positive bus plate 59 and thenegative bus plate 57), the thickness of the materials is a designchoice dependent upon a tradeoff between electrical advantage (e.g.,generally, provided the materials can still perform the desiredelectrical isolation, thinner materials are preferable) and mechanicaladvantage (e.g., if the materials are too thin they may be mechanicallyunstable, and hence may fracture under normal operation). In oneimplementation, the thickness of the materials ranges from 0.1 mm to 1.0mm. In another implementation, the thickness of the materials is 0.3 mm.

[0049] In one implementation, at least a portion of the materials,referred to herein, which have not been herein identified, described,and/or understood by one having ordinary skill in the art as conductiveor semi-conductive, can be composites of materials, such as compositesof plastics and glass. For example, in one implementation the moduleframe 11, the top cover 10, and the electrically insulating layer 51,which have previously been described as composed of plastic, are insteadimplemented as composites of plastic and glass. In one implementation,the electrically insulating layer 51 has a lower glass content and ahigher plastic content in order to provide better dielectric isolation,while the module frame 11, and the top cover 10, have a higher glasscontent and a lower plastic content to provide better mechanicalstability. Those having ordinary skill in the art will appreciate thatglass provides both mechanical strength and dimensional stability (e.g.,glass generally doesn't immoderately expand or contract withtemperature).

[0050] In one implementation, at least a portion of the materials,referred to herein, which have not been herein identified, described,and/or understood by one having ordinary skill in the art as conductiveor semi-conductive, can be used to form various embodiments ofstructures described herein in various ways. For example, in oneimplementation, the electrically insulating layer 51 is formedseparately and mechanically integrated with other components asdescribed herein, while in another implementation, the electricallyinsulating layer 51 is formed of a piece with other components asdescribed herein via an injection molding process (e.g., injectionmolding module frame 11 and the electrically insulating layer 51 as onepiece).

[0051] In various embodiments at least a portion of the materials,referred to herein, which have not been herein identified, described,and/or understood by one having ordinary skill in the art as conductiveor semi-conductive have been implemented using any one or more of thefollowing commercially-available materials: the NOMEX material availablefrom the Dupont Company; Advanced Fibers Systems, 7070 Mississauga Road,Mississauga, Ontario L5M 2H3, Canada; the CIRLEX material available fromthe FRALOCK Company, 120 Industrial Road, San Carlos, Calif. 94070; aPolyphthalamide (PPA) material such as AMODEL AF-1133 VO EngineeringResin available from Amoco Polymers, Inc, 4500 McGinnis Ferry Road,Alpharetta, Ga. 30202-3914; the NORYL GTX830 material available from GEPlastics, One Plastics Avenue, Pittsfield, Mass. 01201; and the HeaterSamicanite material available from Isola Composites, 90101 DELLE France.

[0052] The cooling system is further illustrated in FIG. 5. Heatproduced by the power module is conducted through the base plate 61 andthe conducting projections 111 to the coolant cavities 95. Coolant flowsinto the coolant intake 91, through the cavities 95, and out coolantintake 93, thereby dissipating heat energy from the power module.

[0053] Referring now to FIG. 6, a cross-sectional front view of thepower module without cooling intake and out take is shown.

[0054] Turning now to FIG. 7, a cross-sectional side view of the powermodule with DC bus leads is shown. The coolant cavity 95 runs the lengthof the module to intake 91. The high side substrate switches 55 areshown inside the module 29 with positive DC leads 21.

[0055]FIG. 8 is a cross-sectional side view of the power module withnegative DC bus leads 23 and phase terminals 15, 17, and 19.

[0056]FIG. 9 is a top overhead view of the switching devices 33 anddiodes 35 on the substrate of the module. The positive DC bus plate 59and the negative DC bus plate 57 are also shown.

[0057] Referring now to FIG. 10, a top overhead view of the printedcircuit board in the module is shown. The positive DC bus plate 59 isallowed to extend into a high side slot in the middle of the module, andthe negative DC bus plate 57 is allowed to extend into a low side slotin the middle of the module. The DC bus plate has openings for a passage39 from the high side 101 to the low side 103. Substrate switches 33 anddiodes 35 are shown on a printed circuit board. As stated in thediscussion accompanying FIG. 3, the current must be able to flow fromthe conducting layer on the high side 101 of the substrate to theconducting layer on the low side 103 of the substrate. The current flowsfrom the conducting layer of the substrate on the high side 101, throughthe switches 33 and diodes 35 to the conducting plate 37. The conductingplate 37 is connected through the passage 39 to a plate 73 on the lowside 103 of the module.

[0058] Referring now to FIG. 11 a perspective view of the power moduleand DC bus with the printed circuit board, substrate, and switchesremoved is shown. The DC bus 31 has positive leads 21 connected to thepositive bus plate 57 and negative leads 23 connected to a negative busplate 59.

[0059]FIG. 12 is a perspective view of the DC bus. The DC bus 31 haspositive DC leads 21 connected to a positive plate 59. The positiveplate is in parallel with a negative plate 57, which is connected tonegative DC leads 23. The plates are optionally separated by anon-conducting layer 51. The DC bus 31 has shorter tabs 81 and longertabs 83 for forming a connection with the connecting layer of thesubstrate. Preferably, the tabs 81 and 83 are wire bonded to theconducting layer of the substrate. The DC bus 31 also has openings 85through which connections may be made from the high side of thesubstrate to the low side of the substrate.

[0060]FIG. 13 is a cross-sectional view of the DC bus 31. Anon-conducting layer 51 separates the negative bus plate 57 from thepositive bus plate 59. Positive DC lead 21 and negative DC lead 23 arealso shown.

[0061] The figures disclosed herein are merely exemplary of theinvention, and the invention may be embodied in various and alternativeforms. The figures are not necessarily to scale. Some features may beexaggerated or minimized to show details of particular components.Therefore, specific structural and functional details disclosed hereinare not to be interpreted as limiting, but merely as a basis for theclaims and as a representative basis for teaching one skilled in the artto variously employ the present invention.

[0062] The foregoing described embodiments depict different componentscontained within, or connected with, different other components. It isto be understood that such depicted architectures are merely exemplary,and that in fact many other architectures can be implemented whichachieve the same functionality. In a conceptual sense, any arrangementof components to achieve the same functionality is effectively“associated” such that the desired functionality is achieved. Hence, anytwo components herein combined to achieve a particular functionality canbe seen as “associated with” each other such that the desiredfunctionality is achieved, irrespective of architectures or intermedialcomponents. Likewise, any two components so associated can also beviewed as being “operably connected”, or “operably coupled”, to eachother to achieve the desired functionality.

[0063] While particular embodiments of the present invention have beenshown and described, it will be obvious to those skilled in the artthat, based upon the teachings herein, changes and modifications may bemade without departing from this invention and its broader aspects and,therefore, the appended claims are to encompass within their scope allsuch changes and modifications as are within the true spirit and scopeof this invention. Furthermore, it is to be understood that theinvention is solely defined by the appended claims. It will beunderstood by those within the art that, in general, terms used herein,and especially in the appended claims (e.g., bodies of the appendedclaims) are generally intended as “open” terms (e.g., the term“including” should be interpreted as “including but not limited to,” theterm “having” should be interpreted as “having at least,” the term“includes” should be interpreted as “includes but is not limited to,”etc.). It will be further understood by those within the art that if aspecific number of an introduced claim recitation is intended, such anintent will be explicitly recited in the claim, and in the absence ofsuch recitation no such intent is present. For example, as an aid tounderstanding, the following appended claims may contain usage of theintroductory phrases “at least one” and “one or more” to introduce claimrecitations. However, the use of such phrases should not be construed toimply that the introduction of a claim recitation by the indefinitearticles “a” or “an” limits any particular claim containing suchintroduced claim recitation to inventions containing only one suchrecitation, even when the same claim includes the introductory phrases“one or more” or “at least one” and indefinite articles such as “a” or“an” (e.g., “a” and/or “an” should typically be interpreted to mean “atleast one” or “one or more”); the same holds true for the use ofdefinite articles used to introduce claim recitations. In addition, evenif a specific number of an introduced claim recitation is explicitlyrecited, those skilled in the art will recognize that such recitationshould typically be interpreted to mean at least the recited number(e.g., the bare recitation of “two recitations,” without othermodifiers, typically means at least two recitations, or two or morerecitations).

[0064] Having thus described the invention, the same will become betterunderstood from the appended claims in which it is set forth in anon-limiting manner.

1. A DC Bus for use in a power module, comprising: a positive DC conductor bus plate; a negative DC conductor bus plate placed parallel to said positive bus; one or more positive leads connected to said positive bus, wherein said positive leads are connectable to a positive terminal of a power source; one or more negative leads connected to said negative bus, wherein said negative leads are connectable to a ground terminal; one or more positive connections fastenable from said positive bus to the high side of a power module; one or more negative connections fastenable from said negative bus to the low side of a power module; wherein said positive bus and said negative bus permit counter-flow of currents thereby canceling magnetic fields and their associated inductances; and wherein said positive bus and said negative bus are located between the high side and the low side of the power module.
 2. The DC Bus of claim 1, having separate negative leads and separate positive leads for each half-bridge.
 3. The DC Bus of claim 1, wherein each positive lead corresponds to and is located proximate to each high half-bridge in the power module, and each negative lead corresponds to and is located proximate to each low half-bridge in the power module.
 4. The DC Bus of claim 3, wherein each positive lead is substantially central to the side of the corresponding high half bridge and each negative lead is substantially central to the side of the corresponding low half bridge.
 5. The DC Bus of claim 1, further comprising: an insulating layer in between said positive bus and said negative bus.
 6. The DC Bus of claim 1, wherein each positive lead is substantially adjacent a negative lead.
 7. The DC Bus of claim 1, wherein the positive bus and the negative bus are shaped to be connected substantially perpendicular to the substrate of the power module.
 8. The DC Bus of claim 1, wherein the positive bus and the negative bus are shaped to be connected substantially parallel to the substrate of the power module.
 9. A power module for reducing inductance, comprising: a lead frame for supporting the module and for providing interconnections to the motor and power source; a substrate connected to said lead frame; one or more pairs of high and low switches at the substrate level of the module; a positive DC bus plate connected to the center portion of the power module; a negative DC conductor bus plate placed parallel to said positive bus; one or more positive leads connected to said positive bus, wherein said positive leads are connectable to a positive terminal of a power source; one or more negative leads connected to said negative bus, wherein said negative leads are connectable to ground; one or more positive connections fastenable from said positive bus to the high side of a power module; one or more negative connections fastenable from said negative bus to the low side of a power module; wherein said positive bus and said negative bus permit counter-flow of currents thereby canceling magnetic fields and their associated inductances; and wherein said positive bus and said negative bus are located between the high side and the low side of the power module.
 10. The power module of claim 9, having separate negative leads and separate positive leads for each half-bridge.
 11. The power module of claim 9, wherein each positive lead corresponds to and is located proximate to each high half-bridge in the power module, and each negative lead corresponds to and is located proximate to each low half-bridge in the power module.
 12. The power module of claim 11, wherein each positive lead is substantially central to the side of the corresponding high half bridge and each negative lead is substantially central to the side of the corresponding low half bridge.
 13. The power module of claim 9, further comprising: an insulating layer in between said positive bus and said negative bus.
 14. The power module of claim 9, wherein each positive lead is substantially adjacent a negative lead.
 15. The power module of claim 9, wherein the positive bus and the negative bus are shaped to be connected substantially perpendicular to the substrate of the power module.
 16. The power module of claim 9, wherein the positive bus and the negative bus are shaped to be connected substantially parallel to the substrate of the power module.
 17. A method of reducing inductance in a power module comprising: allowing DC current to flow symmetrically and directly to the switches of the module; permitting counter-flow of electric currents, thereby canceling magnetic fields and their associated inductances; and simultaneously positioning the positive and negative leads in close proximity to one another thereby canceling the magnetic fields and their associated inductance
 18. The method of claim 17, further comprising: mounting a DC positive bus plate and a DC negative bus plate parallel to one another between the high and the low side of the power module.
 19. The method of claim 17, further comprising: placing an insulating layer in between the positive bus and the negative bus.
 20. The method of claim 17, further comprising: providing separate power leads to each half-bridge of the power module.
 21. A power module, comprising: one or more materials interposed between a positive conductor bus plate and a negative conductor bus plate, said one or more materials providing at least one dielectric property; a high side of a substrate operably connected with the positive conductor bus plate; and a low side of the substrate operably connected with the negative conductor bus plate.
 22. The power module of claim 21, wherein the substrate comprises: at least one switch for controlling current flow.
 23. The power module of claim 22, wherein said at least one switch for controlling current flow comprises: at least one power transistor.
 24. The power module of claim 21, wherein said one or more materials providing at least one dielectric property comprise: said one or more materials providing a dielectric strength of substantially 20 kV/mm or greater.
 25. The power module of claim 21, wherein said one or more materials providing at least one dielectric property comprise: said one or more materials providing dielectric isolation from substantially 2 kV to substantially 5 kV.
 26. The power module of claim 21, wherein said one or more materials providing at least one dielectric property comprise: said one or more materials substantially maintaining the at least one dielectric property subsequent to injection molding.
 27. The power module of claim 21, wherein said one or more materials providing at least one dielectric property comprise: said one or more materials having a thickness ranging from substantially 0.1 mm to substantially 1.0 mm.
 28. The power module of claim 21, wherein said one or more materials interposed between a positive conductor bus plate and a negative conductor bus plate comprise: said one or more materials formed of a piece with a module frame.
 29. The power module of claim 21, further comprising: a motor operably coupled to at least one set of phase terminals of said power module.
 30. The power module of claim 21, wherein said power module comprises: said power module operably coupled with a vehicle selected from a vehicle-group including an automobile, an aircraft, a truck, a crane, a locomotive, and a tank.
 31. The power module of claim 21, wherein said power module comprises: said power module operably coupled with industrial automation selected from an industrial-automation-group including an assembly line, a stamping machine, and a lifting device.
 32. A power system, comprising: a power module including one or more materials interposed between a positive conductor bus plate and a negative conductor bus plate, said one or more materials providing at least one dielectric property, a high side of the power module operably connected with the positive conductor bus plate, and a low side of the power module operably connected with the negative conductor bus plate; a DC source operably coupled to the positive conductor bus plate and the negative conductor bus plate; and an AC load operably coupled to at least one set of phase terminals of said power module.
 33. The power system of claim 32, wherein said power module comprises: at least one switch for controlling current flow.
 34. The power system of claim 33, wherein said at least one switch for controlling current flow comprises: at least one power transistor.
 35. The power system of claim 32, wherein said one or more materials providing at least one dielectric property comprise: said one or more materials providing a dielectric strength of substantially 20 kV/mm or greater.
 36. The power system of claim 32, wherein said one or more materials providing at least one dielectric property comprise: said one or more materials providing dielectric isolation from substantially 2 kV to substantially 5 kV.
 37. The power system of claim 32, wherein said one or more materials providing at least one dielectric property comprise: said one or more materials substantially maintaining the at least one dielectric property subsequent to injection molding.
 38. The power system of claim 37, wherein said one or more materials substantially maintaining the at least one dielectric property subsequent to injection molding comprises: said one or more materials substantially maintaining the at least one dielectric property subsequent to being exposed to a temperature of at least approximately 330 degrees centigrade.
 39. The power system of claim 37, wherein said one or more materials substantially maintaining the at least one dielectric property subsequent to injection molding comprises: said one or more materials substantially maintaining the at least one dielectric property subsequent to being exposed to a pressure of at least approximately 50 mega-Pascals.
 40. The power system of claim 32, wherein said one or more materials providing at least one dielectric property comprise: said one or more materials having a thickness ranging from substantially 0.1 mm to substantially 1.0 mm.
 41. The power system of claim 32, wherein said one or more materials providing at least one dielectric property comprise: said one or more materials having a thickness of substantially 0.3 mm.
 42. The power system of claim 32, wherein said one or more materials providing at least one dielectric property comprise: at least a plastic material.
 43. The power system of claim 32, wherein said one or more materials providing at least one dielectric property comprise: at least a glass material.
 44. The power system of claim 32, wherein said DC source operably coupled to the positive conductor bus plate and the negative conductor bus plate comprises: a DC power supply.
 45. The power system of claim 32, wherein said AC load operably coupled to at least one set of phase terminals of said power module comprises: a motor operably coupled to the at least one set of phase terminals of said power module.
 46. The power system of claim 45, wherein said motor operably coupled to the at least one set of phase terminals of said power module comprises: a 3-phase motor operably coupled with three sets of phase terminals of said power module.
 47. The power system of claim 45, wherein said power system comprises: said power system operably coupled with a vehicle selected from a vehicle-group including an automobile, an aircraft, a truck, a crane, a locomotive, and a tank.
 48. The power system of claim 45, wherein said power system comprises: said power system operably coupled with industrial automation selected from an industrial-automation-group including an assembly line, a stamping machine, and a lifting device.
 49. A power bus, comprising: one or more materials interposed between a positive conductor bus plate and a negative conductor bus plate, said one or more materials providing at least one dielectric property; a power module operably connected with the positive conductor bus plate; and said power module operably connected with the negative conductor bus plate.
 50. The power bus of claim 49, wherein said power module comprises: at least one switching device.
 51. The power bus of claim 50, wherein said at least one switching device comprises: at least one power transistor.
 52. The power bus of claim 49, wherein said power module comprises: a power inverter.
 53. The power bus of claim 49, wherein said power module comprises: a power inverter forming at least a part of a power converter.
 54. The power bus of claim 49, wherein said one or more materials providing at least one dielectric property comprise: said one or more materials providing a dielectric strength of substantially 20 kV/mm or greater.
 55. The power bus of claim 49, wherein said one or more materials providing at least one dielectric property comprise: said one or more materials providing dielectric isolation from substantially 2 kV to substantially 5 kV.
 56. The power bus of claim 49, wherein said one or more materials providing at least one dielectric property comprise: said one or more materials substantially maintaining the at least one dielectric property subsequent to injection molding.
 57. The power bus of claim 49, wherein said one or more materials providing at least one dielectric property comprise: said one or more materials having a thickness ranging from substantially 0.1 mm to substantially 1.0 mm.
 58. The power bus of claim 49, further comprising: the power bus operably coupled to a DC power supply.
 59. The power bus of claim 49, further comprising: the power bus operably coupled to a motor.
 60. The power bus of claim 49, further comprising: the power bus operably coupled to a vehicle selected from a vehicle-group including an automobile, an aircraft, a truck, a crane, a locomotive, and a tank.
 61. The power bus of claim 49, further comprising: the power bus operably coupled to industrial automation selected from an industrial-automation-group including an assembly line, a stamping machine, and a lifting device.
 62. A module frame, comprising: one or more materials formed to be interposable between a positive conductor bus plate and a negative conductor bus plate, said one or more materials providing at least one dielectric property.
 63. The module frame of claim 62, wherein said one or more materials providing at least one dielectric property comprise: said one or more materials providing a dielectric strength of substantially 20 kV/mm or greater.
 64. The module frame of claim 62, wherein said one or more materials providing at least one dielectric property comprise: said one or more materials providing dielectric isolation from substantially 2 kV to substantially 5 kV.
 65. The module frame of claim 62, wherein said one or more materials formed to be interposable between a positive conductor bus plate and a negative conductor bus plate comprise: said one or more materials formed of a piece with the module frame.
 66. The module frame of claim 62, wherein said one or more materials formed to be interposable between a positive conductor bus plate and a negative conductor bus plate comprise: said one or more materials mechanically integrated into the module frame. 